Regulatory Capital - U.S. Basel III Regulatory Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Actual Amount
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	$ 2,957,067	$ 3,019,973
Tier 1 Capital (to Risk-Weighted Assets)	2,957,067	3,019,973
Total Capital (to Risk-Weighted Assets)	3,294,663	3,334,140
Tier 1 Capital (to Average Assets)	$ 2,957,067	$ 3,019,973
Actual Ratio
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	11.30%	12.30%
Tier 1 Capital (to Risk-Weighted Assets)	0.113	0.123
Total Capital (to Risk-Weighted Assets)	0.126	0.136
Tier 1 Capital (to Average Assets)	0.097	0.102
Well Capitalized Regulatory Requirements, Amount
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	$ 1,827,318	$ 1,719,621
Tier 1 Capital (to Risk-Weighted Assets)	2,218,886	2,088,111
Total Capital (to Risk-Weighted Assets)	2,740,976	2,579,432
Tier 1 Capital (to Average Assets)	$ 1,213,505	$ 1,184,213
Well Capitalized Regulatory Requirements, Ratio
Common Equity Tier 1 Capital (to Risk-Weighted Assets)	7.00%	7.00%
Tier 1 Capital (to Risk-Weighted Assets)	0.085	0.085
Total Capital (to Risk-Weighted Assets)	0.105	0.105
Tier 1 Capital (to Average Assets)	0.040	0.040